*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins',sans-serif;
}
body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}
.btn{
    padding: 20px 30px;
    position: relative; 
    font-size: 20px;
    font-weight: 700;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    background-image: linear-gradient(rgb(43,190,96),rgb(15,157,88));
    color: #000;
    text-decoration: none;
    border-radius: 5px;
    overflow: hidden;
    transition: 0.5s;
}
.btn:hover{
    color: #fff;
}
.btn span{
    z-index: 1;
    position: relative;
}
.btn::before {
    content: "";
    position: absolute;
    left: var(--x);
    top: var(--y);
    transform: translate(-50%,-50%);
    height: 0;
    width: 0;
    background-color: #000;
    border-radius: 50%;
    transition: width 0.5s, height 0.5s;
}
.btn:hover::before{
    height: 400px;
    width: 400px;
}
